Better LP fee evaluation based on virtual takers not real takers

[davidsiska-vega]

At the moment the LP rewards are distributed based on LP fees received. This is gameable. Instead calculate "virtual LP fees received in quantum" which would be the amount resulting from the of trade notional of one quantum unit, happening at current markprice, once per LP fee evaluation time step. Distribute LP rewards at epoch end relatively based on this accumulate "virtual LP fee received in quantum".

[witgaw]

PR on hold for now.

[barnabee]

To prioritise this it would be useful to add in this ticket the exploit vectors and a brief assessment of the probability and impact of each @davidsiska-vega

[davidsiska-vega]

How to game current setup:

1. as an LP keep badly priced volume most of the epoch.
2. at a chosen time place your volume better so you are scored highly
3. start some wash trading bots (with a different key); this collects trading fees for you and you get most (because of your well priced volume)
4. move your volume out again to reduce position risk
5. at epoch end, rewards distributed based on LP fees received mean that you collect most rewards even if you didn't provide good liquidity (or better than others anyway).

[davidsiska-vega]

Maybe not a big deal; if other LPs on the market notice this, they can do the same thus negating this attack.

[davidsiska-vega]

Close this - won't be an issue with liquidity v3.0